Abstract
The recent white paper on lung cancer has some insights, but also some misconceptionshttp://ow.ly/RZLmM
To the Editor:
我们对欧洲呼吸学会和欧洲放射学会共同发表的有关肺癌筛查的白皮书非常感兴趣[188bet官网地址1]。While it has some thoughtful insights, it also has some misconceptions.
1) Use of evidence. The benefit of lung cancer screening is controversial. Even in the USA, the limits that Medicare put on screening are very substantial in terms of requiring registries and limiting screening centres. There are different recommendations from scientific societies based on the same evidence (age range, ex-smokers inclusion). The American Academy of Family Physicians and others do not even recommend screening [2,3]。The mortality benefit of lung cancer screening is not 20% but rather 16% (20% lower) according to published data using a longer National Lung Screening Trial (NLST) follow-up [4]。这是降低筛选益处的重要一点。在NLST中观察到的肺癌筛查的极其相关的局限性是低阶段。下台是任何筛查计划的核心目标,因为它允许修改疾病的临床过程。NLST的第一轮和第二次发病率显示了I期肺癌的59%和64%,而患病率则为54.6%[5]。Stage I downstaging with lung cancer is below 10%. The authors state that 60–80% of screening-detected cancers will be stage I and this is an overstatement which can lead to misinterpretation [1]。30% of screen-detected lung cancers in incidence rounds are stages III or IV in the NLST.
2) Overdiagnosis. Overdiagnosis exists and is higher than the 18% observed by Patzet al.[6]将计算机断层扫描(CT)与NLST中的胸部X射线照相进行比较时。正如白皮书正确指出的那样,用于肺癌筛查的射线照相在其他研究中也显示出过度诊断[7]。It is logical therefore to think that overdiagnosis is even higher when comparing chest CT with standard practice without screening. Furthermore, overdiagnosis, by definition, biases results towards a better survival. The higher the rate of overdiagnosis in a given screening programme, the higher the benefit achieved (lower mortality and lower adverse effects related to screening).
3) Radiation induced cancers. In our opinion, the White Paper underscores the importance of radiation induced cancers. A person undergoing lung cancer screening would suffer more than 25 low-dose CTs. Considering the number of false positives, even in case of using volumetric criteria to reduce false positives, it is expected that at least one in five incidence screens would be a false positive and therefore need extra image-based work-up. A diagnostic CT uses much more than 2–3 mSv and such screening would occur at least five times in the 25 years of screening. This radiation dose would be higher than that received by atomic bomb survivors or nuclear plant workers (40 mSv) [8]。
4) Cost-effectiveness of health interventions. The cost matters, and lung cancer screening which includes diagnostic work-up of large numbers of positive patients is extremely expensive. $81 000 per quality-adjusted life year (QALY) is a high cost [9],这一估计的上限为186 000美元。前吸烟者的每QALY成本占NLST患者的52%,为615 000美元。我们必须添加肺癌筛查计划的实施成本,这是也很高(购买专用的CTS,专用人员,信息系统等)。烟草戒烟干预措施的每QALY成本在1000欧元至5000欧元之间[10]。It is obvious that the savings obtained by quitting smoking are significant. If we consider the cost-opportunity, smoking cessation reduces the risk of many diseases and extends lifespan an average of 10 years [11]。肺癌筛查的成本也可能有重要的差异,具体取决于欧洲国家的应用。戒烟的成本效益必须包括在肺癌筛查辩论中。
It seems too early to promote lung cancer screening in Europe due to the aforementioned reasons. While lung cancer screening was shown as beneficial in only one study, this benefit is not exempt of risks. The downstaging observed is discrete. It is estimated that lung cancer screening might prevent between 6500 and 8000 annual lung cancer deaths in the USA, 5% of the total annual lung cancer deaths [12]。对于每个1000个筛查的个体,肺癌死亡将从21降低到18(16%)。从不同的角度来看,筛查对肺癌死亡的影响非常低[13]。
Finally, no European study has indicated any benefit related with lung cancer screening and researchers are currently working on a European Lung Cancer pooling study. Recent results of the DANTE (Detection and Screening of Early Lung Cancer with Novel Imaging Technology and Molecular Assays) study do not show any benefit [14], the same as the Danish Lung Cancer Screening Trial [15]。的原因divergence between European studies and NSLT is currently unknown. It might be due to selection bias in NSLT (younger age or higher education of participants) or the selection of excellent participating centres (low surgical mortality). One last reason, but not less important, is the different health system model used in each geographical area. Is there such strong evidence to promote the introduction of lung cancer screening in Europe? Has its cost-effectiveness been demonstrated compared with cheaper alternatives? Are we in such a hurry that we cannot wait some months for the European Pooling or Nelson study results? With the current evidence, lung cancer screening should be restricted to the individual discussion patient-clinician. In our opinion, the white paper is a slippery step forward that might not be beneficial to European patients and that threatens the economic sustainability of European health services.
脚注
Conflict of interest: None declared
- ReceivedMay 28, 2015.
- AcceptedJune 17, 2015.
- 复制right ©ERS 2015